Hi Ryan,
Well firstly welcome to the ODK Forums. As you've already noticed there is plenty of info here on this site that will keep you going til the end of time.
An interesting pair of mowers you have there. Firstly the Diplomat seems quite original and if it still drives then you've got a special one as most of them have had the drive gear fail in them and they haven't been available for many years. The best thing on it is the 3 HP Briggs engine. Personally I'm not a fan of this model at all even though it did win some design awards back in its day.
Now the Model 45 you have there seems to be a bit of a bitsa, firstly the engine is not its original unit as by the time that frame was made SB were fitting 3 HP engines on all 17 inch models. The early 1976 built 2.5 HP unit is from an earlier machine. The lower section of the handle bar is not the matching unit to the top section, also it's been painted black, something SB never did. I would date the chassis itself at around 1980 ~81 due to the sticker depicting the model and serial number which was done when Rover took over Scott Bonnar in 1980 also the colour of it was a short production run colour while Apple Green wasn't available. As proof of age note how the ID sticker on the Diplomat is the same white plastic as the model 45 and the engine on the diplomat is a June 1980 engine which means the mower was probably built around 3 to 4 months after that date. This correlates what I've suggested about the build date of the Model 45.
The bed knife has seen better days and will be due for retirement when the reel is next sharpened.
Let us know once you've got the engine going and how it performs.
Cheers,
BB.
